Photographic printing apparatus



June 9,- 1931. wt. HUEBNER v 1,809,274

PHOTQGRAPHIC PRINTING APPARATUS Filed NOV. 23, 1927 ll Sheets-Sheet l A ans 45- J1me 1931- vv.c. HUEBNER I PHOTOGRAPHIC PRINTING APPARATUS Filed Nov. 23, 1927 ll Sheets-Sheet 3 June 9',- 1931. w. c. HUEBNER I PHOTOGRAPHIC PRINTING APPARATUS Filed Nov. 23, 1927 ll Sheets-Sheet 5 June 9,- 1931 w, HUEBNER 1,809,274

. PHOTOGRAPHIC PRINTING APPARATUS Filed Nov. 23, 1927 ll Sheets-Sheet 6 V/IIII'IIIIII' 4 TEE/Vim W. C. HUEBNER PHOTOGRAPHIC PRINTING APPARATUS June 9,- 1931.

Filed Nov. 23, 1927 ll SheetsSheet 7 June 1931- w. c. HUEBNER PHQTOGRAPHIC PRINTING APPARATUS Filed Nov. 23, 1927 l1Sheets-Sheet 10 11 Sheets Sheet 11 w. c. HUEBNER PHOTOGRAPHIC PRINTING APPARATUS Filed Nov. 23. 1927 Jun9, 1931.

Patented- June 9, 1931 I UNITED STATES PATENT OFFICE c. Hui-mm, or nur'raLo; NEW YORK, assrenon 'ro, mnmm-nnnrs'rnm v ra'rnnrs oonrm, or 31:21:41.0, NEW Yonx 'rnoroemrnro rnm'rme'arraaa'rus Application filed-November 2a, 1927. Serial in. 235,379."

6 inal' prints in any required predetermined and registered position and relative arrangement directly upon the sensitized surfaces of sheet metal or other press plates which are afterwards suitably finished and used in me- 10 chanical, printing presses for printing in one or 'several colors. Such apparatus is used for various purposes, such as for repeating prints from the same transparent printing plate or negative indifferent arrangement, for composing a number of different subjects in predetermined arrangement on a press plate, or for producing a plurality of press.

plates of a given subject to be used in multicolor presses for printing the different colors.

Such apparatus usually comprisesasupport or holder for the sensitized press plate, a support or holder for holding the negative or positive printing plate (hereinafter called the printing plate) in contact with the sensitized surface of said press'plate, means for causing an intimate uniform contact of the sensitized surface with the printing plate, means for vin desired predetermined locations on the sensitized plate, and means for effecting a relative movement between the surfaces of the plates towards and from each other for placing said surfaces into and out of contact,

and for providing clearance between the same during said relative parallel movements therebetween.

surface-so that different portions of the press plate can be located opposite the image on the printing plate, and some of the objects of the invention are to provide a carriage for this purpose of improved and simplified construc tion; also to provide improved means for adjusting and controlling the movements thereof with expedition and extreme accuracy also to provide means for mounting the metal plate holder on said carriage and to provide improved adjusting and controlling means for shifting said means to move said plate holder in said plane in a direction perpendicular to said other movement and to effect such -movement with extreme accuracy and dispatch.

Other objects are to construct apparatus of the character described having improved means for supporting the printing plate; to provide improved and simplified means for accurately and quickly controlling and adjusting the position thereof relative to the sensitized sheet metal plate; to provide novel means for moving Said printin'g plate toward and from said sensitized surface; also to arrange the various adjusting'and controlling devices of the machine so as to be more read ily accessible for operation than have been such means on photoprinting or composing apparatus heretofore lmown; and also to improve such apparatus, generally in the other respects hereinafter set forth.

In the drawings:

Fig. 1 is a front elevation of my improved photographic printing or composing apparatus, embodying the various novel features of the invention.

Fig. 2 is an elevation of the left hand end thereof. i

Fig. 3 is a front elevation of the sheet metal plate holder and the travelling carriage on -which the same is mounted, adjusted and controlled.

Fig. dis a face view on an enlarged scale, of a portion of the swinging frame, rotary adjustable head, and intermediate supporting element upon which the printing plate and its holder are arranged.

Fig. 5 is a fragmentary vertical section on I an enlarged scale on line -.5, Fig. 19, of the F-ig. 8 is a face view' of-a part ofone en d .of the platecarriage, showingthemovable plate,

support, the coarse and fine adj ust-ingmecha;

. nism therefor, and :.also the lock mechanism for connecting the fine adj usting mechanism i to the plate support, for effecting a final, ac

curate adj ustmentthereo-f.

Fig; 9, verticalsectionof said lock mechanism, partly on line 99, Fig, 10.

line 1010,Fig. 9'. D

Fig. 11 is afragmentary face view,'partly in section, of the.coarse and fine adjusting and positioningmechanism for the plate car- .riage.

Fig. 12 is a sectional elevation thereof.

Fig. 13 is afragmentary plan view of the rotary drum orindicator o f-the coarse adj usting mechanism for the plate carriage.

Fig. 14 is a transverse vertical section thereof on line 14.14, Fig. 13.

Fig. 15 is a; transverse section of the mi- Fig. 1O is a horizontal section thereof, on

crometer scale or indicator of the fine adj neting mechanism for the plate carriage, on line 1515, Fig. 12. 1

Fig. 16 is a. fragmentary, horizontal sec tion, on an enlarged scale, of the adjusting or clearance mechanism for moving the printing plate into and out of contact with the sensitized surface of the metal plate.

Fig. 17 is a transverse vertical section thereof, on line 1717, Fig. 16. 5

Fig. 18 is a transverse section thereof, on line 18-18, Fig. 16.

Fig. 19 is atransverse vertical section of the lock mechanism for securing the swinging frame in operative position.

Fig. 20 is a similar view of the vertical coarse adjustment scale for the sensitized I metal plate support or holder.

Fig. 21 is a similar view of the mechanism for effecting the vertical movements of said plate support.

Figs. 22 and 23 are a horizontal and a vertical section respectively thereof on lines 2222 and 23-23, Fig. 21.

Fig. 24: is a transverse vertical section of the fine adjusting mechanism for the meta plate support, on line 24.24, Fig. 8.

Fig. 25 is a front elevation, partly broken away, of the horizontal coarse adjustment scale for the sheet metal plate carriage. I

Fig. 26 is a longitudinal, vertical section thereof, on line 26-26, Fig. 6.

Fig.27 is asimilar v-iew, online 27; .7, Fig. '6.

Fig. 28 is a faceview of the swinging. frame, rotatable, head,- aux-iliary printing plate support. and printing plate holder,witli a printingplate in positi nthere n, as seen with a photocomposing-or painting appa-- f ratns lof t'he vertical type in which prints dr rintei ii sIsm'fe s-ar d p n p ralllv rtical plali s he apparatus. haw n the. drawings m:

p i g r lly an p g tv ho z nt l y movable plate carriageAon 'w-l-rich the sheet.

metal plateX, monntd on aholder A iS sup ported, so that. the sensitized surface .ofthe plate is disposed -in.,a vertical plane somewhat v forwardly ofv the .-various parts. of ;the holder.

A. This holder. is independently movable on the carriage A in a direction perpendiculartp the movements of; said-carriage. Arrangedopposite to and in .front; of. the. plate carriage is a vertically swingingframe B hinged on a stationary main frame G which includes a base D. Qnthe swingfral ne B is secured the rotary head E upon which. a transparent printingplate X; either positive or negative is supported in avertical plane, by means of a negative holderv which is removably secured to a gasket member G, in turnremovably secured on an intermediate negative supporting member H detachably positioned on the rotary head E beforementioned.

The swing frame, together with the parts F, G, H and E carrying the printing plate X, is adapted to swing on the frame G into and out of a plane in which the surface of said printing' plate is parallel with the surface of the print-receiving surface, and the-negative holder and supplementary negative support are also separately movable relatively to the swing frame towards and from said sensitized surface in planes parallel therewith, by novel means, for the purpose of permitting clearance between the printing and print-reoeiving surfaces during the movements of the carriage to different desired positions, and for allowing for variations in the different printing plates.

-Finally precision registering andadjusting means are provided for accurately adj usting and indicating the horizontal travel of the plate carriage A as a whole, similar means being also provided for adjusting and indicating thevertical travel of the plate holder A on said carriage so that any part of the sensitized plate can be accurately positioned relative to the printing plate. A light chamber or hood I is hinged on the swing frame and encloses a suitable source of illumination at the back of said printing plate X for making the exposures of its image upon thickness of a the sensitized surface of themetal plate X.

The stationary frame C of the machine can be of any suitable construction, that shown-comprising the base' 1), before mentioned, which is provided with a-transverse,

upwardly extending housing 10 which is open towards the rearof the machine and from which arises a pair of fixed spaced columns 11. Another pair-of fixed columns 12 are disposed adjacent nd in front of the columns 11, and forwardly of the housing'lO, and which terminate at their lower ends at the latform 13 extending forwardly'from the housing. The upper ends of the columns 11 and 12 are rigidly connected by a transverse .cross beam 14;

The plate carriage A is preferably in the form of an open, rectangular frame comprising upright, spaced and hollow side columns 16 rigidly connected at their upper ends by a horizontal cross bar 17 and at their lower ends by a similar bar 18. Depending from this bar 18 is a pair of caster trucks'19 each having holders can be secured in exactly the same position on the carriage.

j The slides 35, before mentioned, can be of any suitable construction, each slide as shown, comprisinga flat plate '37 from which extend rearwardly a pair of oppositely disposed side members 38 formed to engage over a vertical T shaped guide rail or strip 39 secured to the upright 16, seeFig. 6. Between the top and bottom of the slide the two free ends of a sprocket chain40 are secured thereto, said chainpassing' upwardly: and then downwardly within the hollowside columns 16 over a sprocket 41, and thence over a similar sprocket 42 at the lower end ofthe upright,

Fig. 21. This lower sprocket -is'rotatably mounted on a shaft 44 projecting outwardly through the front wall of the column- 16 and 2 eter and a spiral gear 46'loos ely j ournalled thereon is arranged to mesh with another a pair of ver ically dispose transve se y spiral gear 47 fixedto a transverse horizontal .tatable rollers 20 adapted to travel on a fixed track or rail 21 secured on the base D, and in addition there are provided guide rollers 22 engaging the opposite vertical faces of the track 21 for maintaining the rollers 20 in position on the track and causing the carriage to travel in a straight path thereon. Similar guide rollers 24 depending from the top rail 17 and engaging opposite sides of a horizontal guide rail 25 fixed to the cross beam 14 of the stationary -main frame cooperate to hold the carriage in correct position during its travel. The plate holder A can be of any suitable construction enabling the sheet metal plate X to be detachably secured and stretched'taut thereon. The holder shown includes spaced vertical side bars 31 and top and bottom horizontal bars 32. The particular construction of the plate holder A will not be described in detail as it is intended to cover the same in a separate application for Letters Patent.

The holder, however, is secured to the carriage A, see Figs. 1, 3and 8, by means of laterally extending lugs 33, a pair of which projects from each of the uprights 31 and are formed to be removably connected to correspending lugs 34. These lugs are rigidly attached to the upper 'and lower ends of ver- .ti cally movable slides 35, one of which is shaft 48,-journalled at its opposite'ends in upright extensions ofbrackets 49 fixed to the uprights 16. A corresponding spiral gear 47 on the other end of the shaft causes like movements of the slide atthat side of the machine, the rotation of the shaft being effected by a crank handle 49a at either end thereof. As it is absolutely necessary that the top, bottom and side rails of the plate holder A be maintained in true horizontal and vertical alinement, it is necessary to provide means for individual, initial rotary adjustment of the sprocket wheels 42 relative to their spiral gears 46, so that the holder A can be tilted to a limited extent in a vertical plane for levelling it.

44 and whichis provided with a pair of alined adjusting screws 51 extending inwardly from opposite sides thereof, and engaging opposite faces of a stud 52 fixed to and projecting from the front face of the spiral gear 46. The spiral gear 46 being in mesh with the other gear 47, cannot rotate except when the shaft 48 is turned. Therefore, by appropriate adjustments of the screws 51, the shaft 44 and the sprocket 42 thereon can be given slight rotary adjustments in either direction, relative to, the sprockets, thus effecting slight corresponding movements of the sprocket chain 40. In this way, either sprocket chain can be separately shifted to raise or lower the adjacent end of the plate holder A to tilt said holder, as may be necessary.

The upper sprocket 41 is preferably journalled in a vertically adjustable slide 54 (see Figs. 21 and 22) movable in a guide 55 fixed to the column 16 for tightening the sprocket chain 40 as desired, said slide 54 being moved up and-downbymeans ofadiusting screws. 56,. hav ng threaded connection with said guide.

The, horizontal inovements'o'f the plate carriage A are-effected{through a drive mechanism which inchides a .horihontal, transverse shaft 60.journalled atits opposite ends in secured on .the hfousing and is therein prov ded 1; with a fixed isp ral gea-rli l. This gear meshes with another spiralgear; secured on the front endrof'a rearwardly extending horizontal shaftfiti- -j our-nailed in said casing a-nd'jn 1a beari 11g block 67 rigidly secured at the-roan of saul=lijo1ising 10. The shaft 66,

. rearwardly. beyondthe hearing block 67'is providedwith a spur-pinion 68 meshing with ahorizontal rackfl!) adjustal'ily mounted on a hori-zontalrailg'l'l); fixed atits opposite ends -to the brackets 49, before mentioned, of the carriage A. By turningeitl' er crank 62in one directionoranother, the carriagemay be moved iii-opposite direct ons in a plane parallel with. the sensitized surface. The

coarse registering means for indicating said. travel of the.'cai'1'|age A and for effecting a' final fine precision;.adjustn1ent thereof are constructed sulastantially'as described in my application, Serial No; 120,179, filed July 7,1926,and now Patent 1,668,592, dated May 8, 1928 and entitled Precision registering and for photographic adjusting mechanisms printing and. other machines, now Patent 1,668,592, granted May 8, 1928..'

The indicating means shown for registering the coarse adjustment or travel of the carriage, as above described, in units of measure,

such as one inch, includes two scale drums 75, one of which is rigidly secured at each end of the shaft 60. Eachdrum, see Figs. 11 and 13, is provided. with a spiral, peripheral groove 76 disposed concentrically of the axis of said shaft 60 and into which depends a tongue 77 formed on aslide 78 arranged tomove in a direction lengthwise of the shaft 60 in a horizontal guide 79 fixed to an up- 1 wardly projecting part 80 ,of the adjacent bracket 61. As shown, the guide has an opening 81 of such length as to include substantially the entire width of the-grooved'portion 7 of the drum 75. The slide 78 is formed with a. sight opening 82 provided with a bevelled edge 83 at one side thereof on which is agradnation or index mark 84 extending ad]acent the side of the groove 76.. When the shaft 60 is turned in one direction or another, the

tongue 77, due to its engagement in the groove 76, causes the slide 78 to move endwise in its guide. .At equidistant intervals around the drum 75, there are graduations 85, each space thereof corresponding to said unit of measure oftravel of the-carriage, sothat-as the shaft rotates, the index ma;rk.;84:.will be brought opposite successive graduation's 85,

thus indicating the distance. travelled by, the.

carriage in inches. V

The adp stmg and Indicating means forthe horizontal carnage further includes a" horizontally disposed scale or part 8 6 preferably-associated with the-rack Gil-and having a plurality of accurately-spaced parts,

corresponding to said unit of mefl ure, or; a major fraction thereof, and'a fine-adjustmgmechanism which can be coupled onlocked to said scale after. the coarse adjustment; of the carriage has been made, to etl 'ectafinalzfine movement of the carriage, andiregister this movement in smallfractions o-f thennit. of.

measure,such as in one thousandthsiof an inch. 7

The scale 86, asin said 1?atent 1,668,592, comprises a plurality of separate blocks 87 and 88 arranged in staggered relation to form.

the substantial equivalent ofa rack bar. These blocks are what are known as Johansson blocks, the dimensionsof which are extremely accurate so that they canbe used .as. standards of measurement. Inthe present instance the horizontal width ofeachblock is one half. inch. The blocks are suitably clamped in a holder or support 89 rigidly secured to a substantially horizontal supporting bar or plate 90, the rack bar 69 also being supported by this plate 90, as by rigidly securing said bar on the top face of the scale holder 89.

The fine adjusting mechanism above mentioned is preferably mounted on the housing 10 of the main frame A and comprises a horizontal, transverse shaft 91 journalled in a slide 92, which slide is arranged to have a limited endwise movement in a plane substantially parallel with the path of movement of the carriage A, in the fixed bearing block 67 before mentioned, through lengthwise movement of the shaft 91, which shaft is provided with collarsor parts engaging opposite ends of said slide 92 to prevent relative lengthwise movements between said shaft and slide. The shaft extends outwardly through the 'opposite end walls of the housing 10, each end having a reduced portion on which is fixed a drum or dial 925. The periphery of the dial is provided with one hundred equally spaced graduations. Between each drum and the adjacent end wall of the housing 10, the

shaft has a finely threaded portion '94 formed' 10 and surrounding the threaded portion of I the shaft is a nut or part 95 having a threaded hole in which the shaft screw 94 turns to cause endwise movement of the shaft and of the slide 92. the shaft are provided with cranks or handles 96 for turning it. Thus each revolution The extreme outer ends of of the shaft causes the slide 92 to travel one-- tenth of an inch and such travel is indicated by the dial 93 as its periphery passes beneath a pointer 93a fixed on the nut 95 or other stationary part, while fractions of each revolution are indicated in thousandths of an .it is provided with a pair of spaced fingers 99 adapted, when the slide '98 is movedrearwardly. to closely embrace any one of-the forwardly projecting blocks 87 of said scale.

'Any suitable means may be employed for actuating the slide 98, such as a gear sector 100 journalled in the lower portion of the part 97, and which is secured on a shaft 102 arranged parallel with and below the shaft 91 and journalled at its'ends in the ends of the housing 10 and having at each end, outward- 1y beyond said housing, a crank '103 for turn ing it. Byrocking the shaft 102 in one direction or another, the fingers 99 of the bolt 98 can be moved into or out of engagementwith the scale as described. 1

When it is desired to adjust the carriage A, the shaft 91 and slide 92 are first moved to the extreme left or zero position, as in Figs. 11 and 12, and the shaft 60 operated to shift the carriage along the track 21 by means of the pinion 68 and rack bar 69. The travel of the carriage will be registered in inches by means of the drums 75 on said shaft 60 and when the desired number of whole units or inches has been travelled,-t he shaft '102 is actuated 'to couple the slide or. bolt 98 of the fine adjusting mechanism with the scale bar 86, the blocks of which are so positioned relatively thereto that by stopping the carriage A exactly at the inch graduations on the drums 75, the blocks 87 of the scale and the fingers 99 of the slide 98 will coincide. By now rotating the shaft 91, an endwise movement will be imparted to the slide 92 carrying with it the other slide 98 and moving the carriage until the desired graduation of the drum 93 indicates that the desired fractional part of the unit of measure has been reached.

In this manner the horizontal carriage can be adjusted with accuracy and dispatch and by locating the actuating handles or cranks and the dials for the coarse and fine adjusting mechanisms at opposite ends of the housing, these parts are easily accessible from either end of the machine.

It is necessary that the pitch line of the rack bar 69 be dlsposed in a relation with the top face of the carriage track 20 to prevent bindin or. slackness between said rack'and its dr ving pinion 68 in the movements of the. carriage. For this purpose the horizontal plate 90 to which the rack :bar and the scale 86 aresecured is adjustably solutely parallelmtmnted so as to move relatively to-the stationary cross bar of the carriage. As shown, the rear face of the .plate 90 rests directly against the front face of the cross bar 70 and its opposite ends are embraced by U- shaped clips 105. These clips are rigidly secured to the bar 70 and are each provided with a pair of oppositely disposed adjusting screws 106 extending towards and engaging the upper and lower. edges of the bar 90. Substantially midway of its length, said bar 90 is apertured and tapped to receive the threaded end of a stud 108 which is journalled in and projects forwardly from a rectangular slide block 109 arranged so as'to have a limited vertical movement in an aperture 110 in the fixed bar 70. The portion of the stud which is disposed in the block 109 is the aperture 110. When it is desired to adjust the rack 69 to effect the'parallelism before mentioned, the'stud is loosened slightly. and then by'appropriate adjustments of the adjusting screws 106 on each end of the bar 70, this bar, together withthe scale and rack supported thereby may be tilted on the stud 108 to the required degree, after which the stud is again ti htened and the adjusting screws 106 held" rem-turning by tightening the lock nuts 112 arranged thereon and which bear against the clips 105. By arranging the stud 108 in the vertically slidable block 109, the rack and scale as a whole can also be moved up and down vertically to permit the pitch line of the rack to be disposed at the proper elevation with relation to the pinion 68. 4 l

The vertical slides 35 for the plate holder A are each provided with a coarse adjustment scale 112, Figs. 3 and 20, similar to the horizontal scale 86 just described, for indicating the vertical travel, in inches, ofthe plate holder. Each scale includes a set of blocks 113, 114 arranged in'staggered relation in aholder 115 which is pivotally secured at its lower end on the slide by a stud or bolt 116, and at its upper end, see Fig. 20 by a similar stud 117 which is fixed to the slide and passes loosely through a hole 118 in the scale. The scale has a pair of oppositely disposed adjustin screws 120 which engage opposite faces 0 the stud 117 so that by appropriately adjusting these screws, the scale may be given a slight lateral adjustment for alining it in true vertical relation to the horizontal scale 86. The front face of the scale is provided with graduations 122, and a'fixed pointer 123 on the column 16 cooperating with the, graduations indicates the travel, in inches, of the plate holder A as. effected by the sprocket chain '40 through the medium of the spiral gears '46 and 47 of thesha-ft 48.

A fineadjusting mechanism similar in construction and operation to the fine adjusting and registering mechanism for thehorizontal movements of the carriage A and means for coupling this fine adjusting mechanism with and locking it to the vertical scale 112 a re provided for effecting and indicating the final precise movement of the plate holder A.

In the construction shown, this fine adjusting. and registering mechanism includes a pair of vertical slides 125, one of which is arranged so slide up and down in suitable fixed guides 126 on each of the upright columns 16. Each slide is provided with a fixed; forwardly projecting bracket 127 having a vertically threaded aperture 128 in which turns-a fine screw threaded portion 129 of a short vertical shaft 130. This shaft is journalled'and prevented from en dwise movement in a bearing sleeve 131 formed on the fixed bracket 49, before mentioned. A spiral gear 133 fixed to the shaft 130 is arranged to mesh with a corresponding spiral gear 135 fixed to a horizontal, transverse shaft 136'journalled at its opposite ends in the brackets 49, each end of the shaft being provided with means for engagement with a crank for turning-it,

the cranks 49a of the shaft 48 being detachable and available for this purpose. The upper end of the shaft 130'is provided with a sca le' or drum 140 graduated on itsperiphery in one hundred equal divisions so'thatwhen the shaft rotates the graduations will coopcrate with a pointer 141 fixed to the bracket 127. The screw threaded portion 129 of the shaft 130 is also formed with ten threads to the inch so that when the shaft rotates. the bracket 127 will move lengthwise of the shaft and carry the slide 125 up and down therewith.

For coupling the slide 125 to the scale 11.2, the following mechanism is preferably employed.

Fixed to and movable with each slide 125. approximately on the horizontal centtr of adjustment of the plate holder A is a casing or housing1'45 in which is arranged a horizontally movable slide or bolt 146 having at its inner end a pair of fingers 147 adapted, when-the slide is'mov'ed' inwardly, to closely embrace that one of the blocks 1140f the scale 112, which at the time is alined therewith. The other end of the slide 146 is provided with rack teeth 148 which mesh with a gear sector 149 slidablv keyed to the upper end of a vertical shaft 150. This shaft is journalled at its upper end in the casing 145 and is journalled at its lower end in the bracket 151 fixed to the upright column 16, and below the bracket 161, tin; shaft is providedwith a forwardly projecting gear sector 152 meshing with a corresponding sector 153 fixed to a horizontal rock shaft 154 also j ournalled at its opposite ends in the carriage bracket-49. The opposite ends ofthe shaft are provided withlevers 155 for rocking it. Thus by rocking'the shaft 154, the vertical shafts 150 are turned so as to si multaneously move bot-h bolts or slides 146 into and out of engagementwith the correspending scales 112, so that after the coarse adjustment of the plate holder has been effected, and the fine adjusting mechanism coupled to the scales 112,"as just described, the actuation of the shaft 136 will cause both slides 125 to move up or down, and the plate holder raised or lowered. By keying the gear sector 149 to the shaft 150, this sector can remain in mesh with the rack teeth 148 of the bolt 146. while moving relatively to the shaft 150 d uring the travel of the slide 125.

As shown, the grad-nations 122 of the scales 112 read in opposite directions, or up and down from zero, which is midway of the ends of the scale. and when the slides 35, 125 are in their initial position, said zero graduation is approximately on the horizontal axis'of the plate holder A and-coincident with the pointer 123. To effect an adjustment of the sensitized plate A, the shaft 48 is rotated to raise or lower the plate holder A through the simultaneous movement of the slides 35 until the desired number of inches of travel are indicated by the scale 122 and pointer 123. Then. if it is desired to shift' the carriage an additional, fractional part of an inch, the

lock mechanism is actuated to couple the of each slide 125 is substantially one inch,

so that by first moving the scale drum 140 to either its upper or lower position before coupling theslide 125 to the scale 112, the plateholder can be adjusted up or down a. fraction of an inch when the mechanisms are coupled as described.

Preferably the slides 35 andthe plate A supported thereby are count-crhalanced by a weight disposed within each of the hollow carriage uprights 16, each weight being attached to one end. of a chain or'cahle 157 which passes over a guide sheave 1.58 at the top of" the column and has its other end secured to the upper end of the ad acent slide 35.

The swing frame B is substantially like the swing frames shown in the Various pattents for photographic printing apparatus taken out by me, and comprises a substantially rectangular plate-having a flat, vertical face 160 which, in the operative position of.

the frame is. disposed opposite and in parallel relation to the sensitized surface of the '69 ing stop block is adapted to abut.

sheet metal plate X. The swing frame B is suitably reinforced-by ribs and flanges and is formed with a central, circular aperture '161 around which the open end of the lamp permitting access to the lamp or sourceof illumination therein.

Suitable stop and lock means are provided for arresting the swing frame when it is moved to its operativeposition parallel with the plate carriage and for locking it in such position.- The mechanism shown for this purpose comprises a pair of vertical oppositely movable, sliding bolts 165, 166, disposed with their respective upper and lower ends slidably engaging in guides 167 on the back of the swing frame B adjacent its free end. The inner ends of these-bolts extend adjacent one another into a housing 169 fixed on the swing frame, and are therein provided with racks 168 which mesh with a pinion 170 journalled in said housing; see Fig. 19. Stationary stop blocks 171, 172 fixed to theupper member 25 and base housing 10 respectively of the main frame and having vertical stop faces 17 3 are disposed so that when the frame isswung to-its closed position, the rear faces of the bolts 165, 166 will strikethese stop faces and arrest the movement of the swing frame. The stop faces 173 each terminate in a recess 174 into which the outer ends of the bolts can be projected, by suitable means, as by turning a crank or lever 175 which is fixed to the shaft176 of the pinion 170 outside the housing 169. The engagement of the ends of the bolts in the recesses 174 enables the swing frame to be properly positioned in the exact plane required, and prevents forward and rearward movements thereof.

In order .to'pre-vent sagging of the swing frame, such as would cause inaccurate positioning of the image on the printing plate X, the frame is provided with guide and stop blocks 178, see Figs. 5 and 19, one of which is adjustably positioned for vertical movement in a recess 17 9 in a forwardly extending'portion of each of the bolt guides 167, as by means of'an adjusting stud 179a and locking screws 179?). The stop blocks 171, 172 are provided with forwardly extending projections each having a horizontal face 180 against which the face of the correspond- The faces 180 of the stop blocks 171, 172 terminate in the inclined cam faces 181, so positioned that when the swing frame is moved to its closed position, the blocks 178 engage one or the other of the inclined faces 381 and the blocks central rectangular opening 201.

are guided to and rest on the face 180, thus supporting the swing frame in its exact location. By appropriate adjustments of the blocks 17 8 the correct position of the swing frame is assured.

The rotary or index head E before mentioned, is in the form of a substantially fiat plate having an outer circular peripheral edge portion 181 and a central rectangular aperture 182. The head is detachably secured against and bears on a finished circular track or rib 185 formed on the front face of the swing frame B, Fig. 16, so as to rotate about its axis on said head to effect desired angular adjustments of the printing plate. For rotatably supporting the swing frame, rollers 186 journalled i'n rockers 187 pivotally mounted on the swing frame are positioned to engage the circular edge 181 of the index head at opposite sides and below the center thereof. The index head E, see Fig. 28 is held against the track 185 of. the swing frame by overhanging fingers or portions 188 on said rockers and similar fingers formed on guide blocks 189 which engage over the outer face of the head. The index head is rotated,

see Fig. 28, by a pinion 190 journalled on the swing frame at one side .of the head, and which meshes with a circular rack or external gear ring 191 formed on or adjacent the periphery of said head E. The gear 190 is turned by means of a pinion 192 having a stud shaft 193 formed for the reception of a suitable crank, not shown. When the index head has been rotated to the desired position, it is held therein by fneans of a suitable dog 195 which is movable into and out of engagement with the teeth of the gear ring 191 by a screw 196 on the swing frame, and which and comprises a rectangular flat frame 200 I having side and end members surrounding a The frame 200 is provided with adjustable clips 202 for engaging the bevelled edges of the printing plate X to position and hold sired location thereof.

the same in de- The gasket member G also comprises a ing position of the machine is intended to closely engage the face of the sheet metal plate X. The holder E is disposed within the flange 206 and is rigidly but releasably secured on the rear face of the gasket frame, by suitable leveling and holding means, not

the gasket,whereby it will engage the sensitized surface during exposures of the image.

. dowels 218, Fig. 16.

- The gasket frame G, as previously stated,

is-removably mounted onan intermediate printing plate supporting member H, which is also rectangular and preferably comprises a cast plate-210 having an opening 211 and a substantially flat rear face 212. A pair of dowels or studs 213 projecting from the face 212 are adapted to enter corresponding holes in the gasket frame for positioning this frame on said member H. The gasket frame G is releasably heldin this position by rotatable fingers 215 pivoted on the member H, Figs. 16 and 28.

The rectangular openings 182, 211, 205 and 201are of substantially the same size and are all alined to permit the passage of light through the printing plate to the sensitized surface. V

The member H is accurately and detachably positioned on the: rotary index head E by suitable means, such as a pair of studs or As shown in Fig. 28, one of the dowels is disposed at each side of the opening 182, and to enable the studs to be accurately positioned on the major axis thereof, each stud is adjustably secured in an eccentric bushing 219, which is rotatable in an eccentrically disposed hole in another bushing 220, which in turn is rotatably disposed in a hole in the head E. The bushings are provided with adjusting screws 221, 222 respectively adapted to extend through any one of a plurality of radially disposed holes in flanges of the respective bushings and engage in threaded holes 223, 224. By appropriate rotation of the two bushings, the

dowels 218 can be very accurately positioned,

after which the bushings are held stationary by the screws 221 and 222. The dowels when adjusted are received in closely fitting holes 225 formed in wear plates 226 fixed to the member H.

For releasably holding the member H on the. dowels 218, locking pins 230 are'used, which extend rearwardly through holes 231 in the index head E and through apertures 232 in the member H. Each pin 230 is rigidly but releasably secured in the aperture 232, as by a fixed collar 233 on the pm which is drawn against ashoulder 234 in said'aperture by a lock nut 2 which engages the threaded outer end of the pin and bears againstthe rear facev 212 of said member H.

In the construction shown, means are proyided for yieldingly forcing the member H away from the sheet metal plate towards the rear face of the index head E to provide clarance between the plates during adjustments of the sheet metal plate carriage A or the plate holder A, and mechanism of novel construction isalso provided for forcing the member H, gasket frame G' and printing plate holder F, as a unit in an opposite direc tion, or away from said face in opposition to the action of said yielding means, and for accurately placing said printing plate face X in the plane of and in contactwith the sensitized surface of the metal plate X.

The yielding means referred to preferably comprises an expansion ,coil spring or the like 238, see Fig. 16, surrounding each pin 230 within the hole 231and bearing at one' I end against adjustable tensioning nuts 239 threaded on the front end ofthe pin, and at its rear end against a guide bushing 24Osurrounding the pin 230 and which is fixed to the rear face of the rotary index head. In the retracted position of the member H and parts supported thereby, the guide bushing 240 enters the aperture 232, The pin 230 has a fixed stud 241 which engagesand slides in a slot 242 in the bushing 240 to prevent rotation of the pin and possible loosening of the j lock nut 235.

The novel printing plate clearance mechanism includes a plurality ofrearwardly portion 251 of the stud 245 is threaded to cxtend through and turn in said portion 250 for imparting lengthwise movements to said stud. The extreme rear end of the stud bears against a flatface 252 of'a hardened disk secured in'the member H with said face 252 disposed substantially in the plane of the front face 2530f said member.

It will be seen that if all of the studs-245 are simultaneously rotated, for instance, in a direction to retract their threaded portions 250, the member H will follow the studs and move away from the printing planeQdue to the action of the springs 238, while a reverse rotation of the studs will move said member toward the printing plane'against the action of said springs.

The means provided for effecting such simultaneous rotation of the studs 245 includes a gearp'inion 255 fixed to the rear end of the body portion 246 of each stud, these pinions all being disposed so as to mesh with a circular, internal gear ring 256 mounted on the rear face of the index head E concentric with its axis and which is adapted to have independent rotation relative to said head. The teeth of said ring are of such widththat the pinions 255 will remain in mesh therewith during the endwise movements of the studs 245.

The gear ring 256 can be rotatably supported on the rotary head E in any suitable manner, as by fingers or projections 259 engaging over a peripheral flange 260 on said ring, said fingers being formed-on blocks 261, secured to the head. Each block 261 is provided with a pivoted roller'262 which bears against the circular ed eof said flange 260, thus providing an anti: riction support on which the ring can turn freely.

The mechanism for causing the rotation of swing frame, preferably adjacent the left hand stationary post 12 of the main frame C. J ournalled in one side of the casing is a transverse, horizontal shaft 266, and secured thereon, interiorly of said casing is a spiral gear 267 meshing with a corresponding gear 268. The gear, together with a spur pinion 269 is formed respectively on the front and rear ends of a sleeve 270, ournalled to rotate about a fixed horizontal shaft 271 extending through the open rear end of said casing into a hole in a supportin bracket or member 272 fixed to the face 0 the swing frame B. The shaft is rigidly secured in said supporting member by a pin or key 273.

Formed on or secured to one side of the supporting member 272 and extendin within the opening 161 of the swin frame there is a bearing 275 in which is ournalled a longitudinal, horizontal stub shaft 276, on the front end of which is secured a gear wheel 277 arranged to mesh with the spur pinion 269 before mentioned. The rear end of said shaft is provided with a spur pinion 278 meshing with the gear ring 256.

It will be seen that by rotating the shaft 266, the gear ring 256 will be turned through the gear train described'to simultaneously actuate all of the studs 245.

The clearance movement of the printing plate, through the mechanism described is preferably a predetermined, fixed distance, for example, one-half inch, the extreme forward position being located by the engagement of the body portions 246 of the studs with the bottoms of the apertures 247, while the rearward movement of the parts is limited, and the retracted position thereof is secured by means of a fiat, forwardly projecting head 258 on each of the guide bushings 248 which is disposed so as to be engaged by the faces 252 on the member H.

The means shown for indicating this movement of the printing plate X towards and from the printing plane through the lengthwise movement of the studs 245, see Fig. 17, includes a gear 280 arranged in the casing 265 and adapted to be rotated by the movements of the spiral gear 268. This gear 280 is fixed to the inner end of a stud or short shaft 281 j ournallcd in the hub of a dial 282 fixed to the front of the casing 265. The stud 281 has a finger or pointer 283 fixed to its front end and which is adapted to rotate past graduations 284 on the dial. For rotating the pointer 283, the gear 280 is disposed in mesh with a small pinion 285 fixed on a stud-286 rigidly se- .cured on the axis of the shaft 270 in a cap or spider 287. This cap 287 surrounds the front end of the shaft 271 and is fixed to a bearing shell 288 which is attached to the spiral gear 268 and carries a ball bearing 289 rotatably embracing the front end of the shaft 271 and which is held against a shoulder 290 on said shaft as by a collar 291. Thus the pinion 285 turns with the gear 268 and the ratio of the gearing described is such that the pointer 283 makes one complete revolution for the full half inch of travel of the printing plate and, as the dial 282 is of ample size, relatively widely spaced and easily read graduations 284 can be used to accurately indicate small movements of the screw studs 245. The shaft 266 can be turned in any suitable manner, the

means shown comprising a transverse, horizontal operating shaft 295 which is journalled and has a limited endwise movement in a bearing bracket 296 fixed to the upright post 12 adjacent the casing 265. The shaft 295 is alined with the shaft 266 and has a clutch member on one end adapted to engage a corresponding member on the adjacent end of said shaft 266, when the shaft 295 is moved to the right, Fig. 4, to couple the two shafts together. For rotating the connected shafts, the left hand end of the shaft 295v is provided with a crank handle 297. Any other suitable means can be employed for actuating the clearance mechanism.

For effecting the necessary close and intimate contact between the printing and sensitized surfaces, suction is made use of, in the present apparatus, hence the provision of the gasket strip 207 on the member G, which engages the surface of the sheet metal plate X around about the printing plate X. Since the walls or flanges 206 of said member G are at a distance from the edges of the plate holder F, a chamber 300 is formed in which the suction can be maintained. The inner adjacent edges of the plate holder and gasket 

